Sediqqi also added that initial reports show that up to five armed men stopped the foreigners' vehicle and carried out the kidnapping. The two abducted are both men, he said. He did not reveal any more details except to say that an investigation is underway.

"Due to privacy and security considerations we will not be commenting further. We continue to advise Australians not to travel to Afghanistan because of the extremely dangerous security situation, including the serious threat of kidnapping," it said.

Senior staff at the university in Kabul could not immediately be reached for comment.

Kidnappings are not uncommon in Afghanistan. Three other foreigners who were kidnapped in Kabul over the past year have all been released, including an Indian woman, Judith D'Souza who was freed last month after being held for more than a month.

An Australian woman, Kerry Jane Wilson, was abducted in the eastern city of Jalalabad in April. Her whereabouts are unknown.

Sediqqi said that kidnappers in all the Kabul cases, including Monday's, had been wearing military uniforms, establishing a pattern and hinting at some form of organized gang activity.

Most of the thousands of foreigners living and working in Kabul are largely confined to their embassies or, in the case of those working for the United Nations or other non-government organizations, to their residential compounds, with limited movement permitted.

The abductions heighten the risk for the few foreigners, including journalists, who move with relative freedom across the Afghan capital in order to do their work.

Residents of the capital complain that crime has risen in recent months, especially robbery and car theft. The apparent rise coincides with an economic crisis as the government has not been able to create jobs or stimulate growth.